The proposed project is designed to uncover the neural correlates of processing two languages as bilinguals transition from novice to intermediate L2 speakers in early childhood. To achieve this, the proposed project will use functional Magnetic Resonance Imaging (fMRI), which measures neural activity indirectly via changes in deoxyhemoglobin which is correlated with blood flow and energy metabolism. Recent research has found that both age of second language acquisition (L2 AoA) and language proficiency play a role in bilingual language processing at the neural level. Research with early L2 child learners in the United States indicate that bilinguals transition from L1 to L2 dominance during the first five years of schooling and maintain a pattern of L2 dominance into adulthood. To elucidate the nature of the neural correlates of bilingualism in child L2 learners, the proposed project will test bilingual children at age 8, 10, and 12, which correspond to time points corresponding to early stages of L2 acquisition up to more advanced L2 knowledge. Children will be asked to repeat auditorily presented words while being scanned with fMRI. The results from the proposed studies will help to elucidate the neural substrates that differentiate first from second language acquisition during childhood. Finally, the proposed studies will compare predictions from two competing models which view L2 acquisition as involving differential use of procedural and declarative memory or involving changes in sensorimotor processing. PUBLIC HEALTH RELEVANCE: The proposed project is designed to uncover the neural correlates of processing two languages as bilinguals transition from novice to intermediate L2 speakers in early childhood. The results from these studies should help to provide background which will help clinicians in the assessment and treatment of young L2 learners with language disorders.